This proposal is an application for the continuation of Public Health Service Grant HL-11119. Its purpose is to make available a common amino acid analyzer and sequencer operation for eight research groups in the Departments of Biochemistry and Molecular Biology and Biological Sciences, by providing support for an operator and the supplies and maintenance for the available equipment. The present research projects dependent on these facilities include the mechanisms of enzyme catalysis (M. Bender); the isolation of antigenic peptides from lactate dehydrogenase C4 (E. Goldberg); the comparative biochemistry of oxygen-carrying proteins (I.M. Klotz); the structure and function of photoreceptor complexes in photosynthesis (P. Loach); enzymes and proteins of coagulative processes (L. Lorand); the mitochondrial metabolic role of cytochrome c (E. Margoliash); the antigenicity of globular proteins (E. Margoliash); the biosynthesis of bacterial cell wall components (F. C. Neuhaus); the structure and function of porphobilinogen synthase (D. Shemin); and the mechanism of action and design of antitumor agents (R. B. Silverman). These studies are supported by the Public Health Service and the continued existence of a joint amino acid analysis and sequencer operation is the most economical way of providing for their prosecution while obviating the duplication of efforts and its resultant inefficiency.